XE Currency Data API - FAQ

Answer

Currencies are always quoted in pairs. The first currency is called the base currency, and the second is called the counter currency. In general terms, the base currency is the currency in which you want to convert from, and the counter currency is the currency you want to convert to.

For example, if your business is in the United States and your systems are based in USD, then you may specify USD as your base currency. This means that all the currency rates in your API results (the counter currencies) will be quoted in relation to USD.